Voltolization of hydrogenated products



March 19B, 1941. W J, SWEENEY 2,235,124A

' vomouzwrron or HYDROGEMTED Pmouuc'rs Filed Dac. 30, 1937 OLVEI'VT EXTRACTING AGENT' MATERIAL MA 72E/A L fo .29E X7-Raar@ SoLu/EN'T 5 6*/ 'Rec o VE nv il` Mar. 1s, 1941 up 2,235,124

VOLTOLIZATION OF HYDROGENATED PRODUCTS William J. Sweeney, Elizabeth, N. J., assigner' to Standard Oil Development Company, a corporation of Delaware Application December 30, 1937, Serial No. 182,440

1 Claim. (Cl. 2011-168) rlhe present invention relates to a process of tracting may vary widely. It is preferred, how- ,producing improved lubricating materials and ever, to use petroleum hydrocarbons as, for exthe products thereof. `It relates to the producample, light, middle or heavy mineral oils, naphtion of oxidation resistant lubricating oils havtha, gas oils, burning oils and the like. Preing high viscosity and high viscosity indexes. ferred materials are petroleum hydrocarbons It particularly relates to the process of proboiling in the lubricating oil range. Preferred ducing these materials from initial materials extracts are those which are secured in the which heretofore have had relatively little value process of refining lubricating oils by solvent and which are produced in lubricating oil solvent treating methods.' In this process lubricating treating processes. These initial materials are oils, usually paraiiinic in nature, having gravilll secured from the extract when solvent extractties A. P. I. from 25 to 35 and a iiash of from ing agents having a preferential selectivity for 300 F. to 500 F. and higher and a viscosity compounds having a lower ratio of hydrogen Saybolt of from 200 at 100 F. to 140 at 210 F. to carbon, as compared to compounds having a are fed into a solvent treating unit. This unit higher ratio of hydrogen to carbon, are emmay be a batch treating apparatus but is prefployed. If solvents are employed which have a erably a continuous treating plant having one o r preferential selectivity for compounds having more individual units. In this unit the feed maa higher ratio of hydrogen to carbon, as comterials are intimately contacted with solvent and pared to compounds having a lower ratio of the desirable saturated paraiinic type of matecompounds to carbon, the initial materials are rials are separated from the relatively unsatfound in therainate. The process of the .presurated and aromatic type of materials. Solent invention segregates these initial aromatic vents having a preferential selectivity for the type materials and. hydrogenates them under former type of materials as, or example, liquid suitable non-cracking conditions and then voltnormally gaseous hydyrocarbons, may be emolizes the hydrogenated product. ployed as, for example, liquid propane and butane.

The invention may be readily understood by Solvents having a preferential selectivity for reference to the attached drawing illustrating one compounds having a lower ratio of hydrogen to modification of the invention. Suitable matecarbon may be employed as, for example, furrial forthe solvent treatment step is fed into fural, liquid sulphur dioxide, phenol, nitrobensolvent treating unit I through feed line 2 where zene, cresylic acid, acetonitrile, aniline, acetone, 30 it intimately contacts a solvent. In the flow and the like. plan illustrated, a solvent having a preferential The conditions of solvent extracting are adselectivity for compounds having a lower ratio justed for the particular feed stock being treatof hydrogen to carbon is employed as, for exed, the solvent being used and the desired quality ample, phenol. This solvent is fed into solvent and yield of the products. The temperature is treating unit i by means of feed line 3. The preferably in the range from 20 F. to 250 F. raffinate or the treated material is removed and the ratio of the volume of solvent to volthrough line 4 while the solvent containing the urne of oil treated is preferably from 1/2 to 10. extract is removed through line 5 and then fed lFor example, when phenol isemployed,` the into the solvent recovery unit 6. In this unit phenol to oil ratio varies from 100 to 200% de- 40\ the solvent is removed from the extract by known pending upon the stock handled and the desired methods and taken ol by means of line 3. The quality of the treated oil. The temperature emextract is removed from the solvent recovery unit ployedis in the range from 100 to 250 F. In 6 by means of line 1 and led into the hydrogenageneral higher temperatures and higher ratios tion unit 8 in which it is hydrogenated by means of phenol to oil results in an improvement in 45 of hydrogen fed into said unit by means of line quality of the raffinate and with a higher yield 0. The hydrogenated extract is removed through .of the extract. For each particular stock treatline il] and led into voltolization unit Il in ed, optimum conditions of temperature and solwhich it is treated with the silent electric glow vent oil ratio must be determined in order to sedischarge in order to secure the product desired. cure the desired products. The nished voltolized hydrogenated extracted The spent solvent containing the extract. may product is removed through line I2 and may be be separated from the raffinate either by gravity used as such or may be segregated into a parsettlingr or by other means as, for example, ticular fraction desired by suitable known means. centrifuging. If a solvent of the type of phenol The initial materials suitable for solvent exis employed, the spent solvent is then taken to a solvent recovery plant in which the solvent is removed from the extract. The yield of the extract may vary widely, depending upon the conditions under which the initial materials are treated. Preferred materials are secured by extracting petroleum lubricating hydrocarbons with a phenol under conditions whereby the spent phenol contains approximately 10 to 30% extract.

The extract after the removal of the solvent is then led to a hydrogenation unit in which it is hydrogenated under suitable conditions. It; is desired to hydrogenate the extract under substantially non-cracking conditions and to secure a substantially saturated product. This is secured by hydrogenating at temperatures below r150" F. in the general range inwhich there is little or no decomposition of the oil. The temperatures and pressures employed depend particularly upon the material to be treated, as well as the catalyst employed and on the duration of the treatment. Thus temperatures up to 850 may be employed providing the duration of the treatment is adjusted so that substantially no cracking occurs. preferably in the range of from 10 to 20 atmospheres although pressures as high as 100 to 200 atmospheres may also be employed. The hydrogenation of the oil under conditions to secure substantially no cracking and to secure substantially a saturated product is very important. This is necessary in order to secure a product which is susceptible to subsequent voltolization and is necessary in order to give desirable voltolization products.

'I'he hydrogenated product is then subjected to voltolization. The process of voltolization consists in subjecting material to the effect of the high tension silent electric discharge, commonly known as the glow discharge. The process of voltolization Varies from .001 mm. to .01 atmosphere, .5 atmosphere, or even as high as .8 atmosphere and higher. It is preferred, however, to have the pressure below one atmosphere. 'Ihe voltages used are preferably in the range from The pressures employed are perature of the mixture to 300 C. and higher.

It may be desirable to voltolize at temperatures below 0 C. as, for example, at a temperature as low as 40 C.

The voltolization operation is continued for a time suiicient to secure a product having the desired viscosity. Preferred products are those having viscosities in the range from 100 to 8,000 Saybolt at 210 F.

The above invention is not to be limited by any theory ormethod of operation but only by the following claim in which it is desired to claim all novelty in so far as the prior art permits.

I claim: y 'Ihe process which comprises treating a petroleum lubricating oil fraction having an A. P. I. gravity of 25 to 35, a iiash of from 300 F. to 500 F. and a Saybolt viscosity from 200 seconds at 100 F. to 140 seconds at 210 F. with a selective solvent adapted to separate compounds having a lower ratio of hydrogen to carbon from compounds having a vhigher ratio of yhydrogen to carbon, separating the resultant oil fractions, hydrogenating the fraction having the lower ratio of hydrogen to carbon and-which is substantially free from parafnic hydrocarbons, under substantially non-cracking conditions to secure substantially a saturated oil, and then voltolizing the resultant hydrogenated oil to a viscosity in the range of 100 to 8,000 seconds Saybolt at 210 F.

WILLIAM J. SWEENEY. 

